1. Field of the Invention
This invention relates to a flame retardant alkylene-alkyl acrylate copolymer composition comprising alkylene-alkyl acrylate copolymer, halogenated flame retardant additive and at least one of calcium or magnesium oxide, carbonate, hydroxide, or sulfate. Also included herein is a flame retardant additive masterbatch comprising alkylene-alkyl acrylate copolymer, halogenated flame retardant additive and calcium or magnesium oxide, carbonate, hydroxide or sulfate.
2. Description of the Prior Art
It is well known that the properties of polyolefins (including copolymers thereof, such as alkylene-alkyl acrylate copolymers) particularly physical properties such as strength, moisture resistance, chemical inertness and its outstanding electrical properties, make it suitable for wire insulation, cable jacketing and other applications. However, it is known that polyolefins and copolymers thereof, such as alkylene-alkyl acrylate copolymers, are quite flammable.
To date, these polyolefins are rendered flame retardant, in commercial applications, primarily by using a synergistic mixture of a halogen containing compound in admixture with an organic or inorganic antimony compound, e.g. antimony oxide. This mixture of halogen containing compound and antimony oxide is a very effective commercial flame retardant and does not reduce the desirable properties of the polyolefins. However, there are several disadvantages in the use of antimony oxide in the flame retardant polyolefin formulation. These disadvantages include: dense smoke production on burning; acidic and corrosive gas evolution on burning; existence of afterglow on burning; handling problems because of its known toxicity, as well as its high cost.
Therefore, a need exists to develop new flame retardants for polyolefins which will render it flame retardant without the undesirable characteristics attributable to antimony oxide. Also, to be effective, any such flame retardant additive(s) should not reduce the desirable physical properties of polyolefins.